Few studies have examined the effect of prophylactic or therapeutic estrogen supplementation on irregular bleeding in DMPA users. A randomized trial (n=132) of cyclic transdermal estradiol 0.1 mg/day (Climara) for 3 months versus placebo in women initiating DMPA immediately post-abortion showed no difference in continuation rates at 12 months; however, the authors of this study reported a high rate of non-compliance with the study protocol and lacked an adequate sample size to detect a difference (Goldberg). This is the only study to report on prophylactic estrogen supplementation in DMPA users.